This invention relates to a plug for a cylindrical passage and in particular to a self contained, inflatable plug for stopping the flow of fluid from a cylindrical pipe, tube or hole in the ground.
Often when drilling holes in the ground, e.g. shot holes for explosives, water is encountered. The water may be under high pressure and flow to the surface, flooding the surrounding area. One method of dealing with the problem is to place an inflatable plug in the hole and inflate the plug to block or seal the hole. In accordance with one current practice, an inflatable plug is placed in the hole and air from a truck mounted compressor is pumped into the plug through tubing connecting the plug to the surface. The method has certain drawbacks such as the expense of the equipment, and the time and difficulty of transporting the equipment and operating personnel to the site.
Other hole sealing plugs are disclosed by U.S. Pat. Nos. 2,671,510 issued to T. B. Slick et al on Mar. 9, 1965; 3,491,798 issued to J. J. Beshara on Jan. 27, 1970; and 3,918,520 issued to S. O. Hutchison on Nov. 11, 1975. The Slick patent discloses a well packer which is inflated by gas generated by an explosion within a cylinder. Beshara proposes an expansible plug which is caused to expand by the detonation of an explosive charge. The Hutchison patent describes a well packer containing a high pressure gas, which is released to expand the packer by a valve controlled by a sequencing timer actuating device.
From a review of the prior art methods and apparatus, it is readily apparent that there exists a need for a simple yet effective plug for stopping the flow of fluid from a cylindrical passage, e.g. a shot hole. The object of the present invention is to at least alleviate the problems referred to hereinbefore by providing a relatively simple, self-contained plug for cylindrical passages. By self-contained is meant a device which can readily be carried to a hole site without any heavy accessory equipment such as a compressor.